AMPHASTAR PHARMA (AMPH): Ownership & Insider Activity
Hedge funds and institutional managers reporting a position in AMPH · Health Care. Based on the most recent 13F filing from each holder, sourced from SEC EDGAR.
Reported Holders
17
13F filers
Aggregate Value
$67.8M
Across holders
Last Price
$21.52
2026-08-24
Sector
Health Care
GICS
Quarterly fund activity9 increased8 reduced1 exited
Full exits: Verition Fund Management LLC
| Manager⇅ | Type⇅ | Shares⇅ | Market Value▼ | % of Total⇅ | % of Portfolio⇅ | Action⇅ | QoQ Change⇅ | Quarter⇅ |
|---|---|---|---|---|---|---|---|---|
| MARSHALL WACE, LLP CIK 0001318757 | Hedge Fund | 1.07M | $21.5M | 31.7% | 0.0% | Added | +$21.1M | Q2 2026 |
| SHAW D E & CO INC CIK 0001009207 | Hedge Fund | 887K | $17.9M | 26.4% | 0.0% | Added | +$17.0M | Q2 2026 |
| RENAISSANCE TECHNOLOGIES LLC CIK 0001037389 | Hedge Fund | 525K | $10.6M | 15.6% | 0.0% | Reduced | $-581K | Q2 2026 |
| TWO SIGMA INVESTMENTS, LP CIK 0001179392 | Hedge Fund | 248K | $5.0M | 7.4% | 0.0% | Added | +$2.2M | Q2 2026 |
| AQR CAPITAL MANAGEMENT LLC CIK 0001167557 | Hedge Fund | 209K | $4.2M | 6.2% | 0.0% | Added | $-5.3M | Q2 2026 |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP CIK 0001164508 | Hedge Fund | 117K | $2.4M | 3.5% | 0.0% | Reduced | $-4.2M | Q2 2026 |
| Squarepoint Ops LLC CIK 0001642575 | Hedge Fund | 79K | $1.6M | 2.3% | 0.0% | Added | +$1.0M | Q2 2026 |
| Point72 Asset Management, L.P. CIK 0001603466 | Hedge Fund | 55K | $1.1M | 1.6% | 0.0% | Added | — | Q2 2026 |
| VOLORIDGE INVESTMENT MANAGEMENT, LLC CIK 0001556921 | Hedge Fund | 51K | $1.0M | 1.5% | 0.0% | Reduced | $-2.4M | Q2 2026 |
| Brevan Howard Capital Management LP CIK 0001512857 | Hedge Fund | 34K | $690K | 1.0% | 0.0% | Added | +$456K | Q2 2026 |
Added
Hedge Fund
$21.5M· 31.7% of total· 0.0% port· 1.07M sh· +$21.1M QoQ· Q2 2026
Added
Hedge Fund
$17.9M· 26.4% of total· 0.0% port· 887K sh· +$17.0M QoQ· Q2 2026
Reduced
Hedge Fund
$10.6M· 15.6% of total· 0.0% port· 525K sh· $-581K QoQ· Q2 2026
Added
Hedge Fund
$5.0M· 7.4% of total· 0.0% port· 248K sh· +$2.2M QoQ· Q2 2026
Added
Hedge Fund
$4.2M· 6.2% of total· 0.0% port· 209K sh· $-5.3M QoQ· Q2 2026
Reduced
Hedge Fund
$2.4M· 3.5% of total· 0.0% port· 117K sh· $-4.2M QoQ· Q2 2026
Added
Hedge Fund
$1.6M· 2.3% of total· 0.0% port· 79K sh· +$1.0M QoQ· Q2 2026
Added
Hedge Fund
$1.1M· 1.6% of total· 0.0% port· 55K sh· — QoQ· Q2 2026
Reduced
Hedge Fund
$1.0M· 1.5% of total· 0.0% port· 51K sh· $-2.4M QoQ· Q2 2026
Added
Hedge Fund
$690K· 1.0% of total· 0.0% port· 34K sh· +$456K QoQ· Q2 2026
Reduced
Hedge Fund
$642K· 0.9% of total· 0.0% port· 32K sh· $-6.9M QoQ· Q2 2026
Reduced
Hedge Fund
$350K· 0.5% of total· 0.0% port· 17K sh· $-401K QoQ· Q2 2026
Reduced
Hedge Fund
$328K· 0.5% of total· 0.0% port· 16K sh· $-995K QoQ· Q2 2026
Reduced
Hedge Fund
$220K· 0.3% of total· 0.0% port· 11K sh· $-7K QoQ· Q2 2026
Added
Hedge Fund
$205K· 0.3% of total· 0.0% port· 10K sh· — QoQ· Q2 2026
Added
Hedge Fund
$36K· 0.1% of total· 0.0% port· 2K sh· — QoQ· Q2 2026
Reduced
Hedge Fund
$141· 0.0% of total· 0.0% port· 7 sh· $-2K QoQ· Q2 2026
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